Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755031AbcD0ARv (ORCPT ); Tue, 26 Apr 2016 20:17:51 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:40079 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753961AbcDZXN4 (ORCPT ); Tue, 26 Apr 2016 19:13:56 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Yoshihiro Shimoda" , "Felipe Balbi" Date: Wed, 27 Apr 2016 01:02:21 +0200 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 167/217] usb: renesas_usbhs: fix to avoid using a disabled ep in usbhsg_queue_done() In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8426:ae4:c500:9cba:69ae:962d:6167 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1616 Lines: 47 3.16.35-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Yoshihiro Shimoda commit 4fccb0767fdbdb781a9c5b5c15ee7b219443c89d upstream. This patch fixes an issue that usbhsg_queue_done() may cause kernel panic when dma callback is running and usb_ep_disable() is called by interrupt handler. (Especially, we can reproduce this issue using g_audio with usb-dmac driver.) For example of a flow: usbhsf_dma_complete (on tasklet) --> usbhsf_pkt_handler (on tasklet) --> usbhsg_queue_done (on tasklet) *** interrupt happened and usb_ep_disable() is called *** --> usbhsg_queue_pop (on tasklet) Then, oops happened. Fixes: e73a989 ("usb: renesas_usbhs: add DMAEngine support") Signed-off-by: Yoshihiro Shimoda Signed-off-by: Felipe Balbi Signed-off-by: Ben Hutchings --- drivers/usb/renesas_usbhs/mod_gadget.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/usb/renesas_usbhs/mod_gadget.c +++ b/drivers/usb/renesas_usbhs/mod_gadget.c @@ -137,10 +137,14 @@ static void usbhsg_queue_done(struct usb struct usbhs_pipe *pipe = pkt->pipe; struct usbhsg_uep *uep = usbhsg_pipe_to_uep(pipe); struct usbhsg_request *ureq = usbhsg_pkt_to_ureq(pkt); + unsigned long flags; ureq->req.actual = pkt->actual; - usbhsg_queue_pop(uep, ureq, 0); + usbhs_lock(priv, flags); + if (uep) + __usbhsg_queue_pop(uep, ureq, 0); + usbhs_unlock(priv, flags); } static void usbhsg_queue_push(struct usbhsg_uep *uep,